Acute coronary syndrome due to coronary artery compression by a metastatic cardiac tumor

A 60-year-old female without coronary risk factors was admitted to the hospital with ST-elevation acute coronary syndrome (ACS). She had previously suffered breast cancer and received radical mastectomy followed by chemotherapy and radiation. Emergent coronary angiography showed an occlusion of the proximal left anterior descending coronary artery (LAD) and coronary angioplasty was performed. Coronary computed tomography (CT) angiography (CTA) disclosed a tumor invading the left ventricular anterior wall and surrounding the coronary artery. Myocardial single-photon-emission CT (SPECT) using 123I-BMIPP showed a defect in the same portion. A fusion image of the CTA and the SPECT delineated a tumor surrounding the coronary artery. She finally died two months later from a terminal condition. Autopsy demonstrated a tumor involving the left ventricular anterior wall and surrounding the LAD. Pathology of the affected LAD showed only fibrous plaque without vulnerable plaque, thrombus, or tumor invasion to the coronary wall. Thus, compression of the coronary artery by the metastatic tumor was the most likely mechanism of ACS.